Electric cut-out



Aug. 8, .1939.

R. S. BENNETT ELECTRIC CUT-OUT t y pm e a 7n n 8 Na on W 0 wax; 7 w www Q m w v. m A %%m%//% Patented Aug. 8, 1939 UNITED STATES PATENT OFFICE ELECTRIC CUT-OUT New York Application November 16, 1937, Serial No. 174,792

13 Claims.

The present invention relates to electric cutouts, more particularly fuse cutouts employing expulsion type fuse holders, and has for an object the provision of improved means for pre- 5 venting short-circuiting arc-over between conducting parts of a fuse cutout upon fuse operation attended by discharge of gases from the fuse holder or holders of the cutout.

One of the more specific objects of the inven- 10 tion is the provision of improved gas. barrier means for isolating from each other the spaces around the terminal contacts of a fuse cutout of the enclosed type.

Another object is the provision in a fuse cut- 5 out of the circuit reclosing type, of improved construction and arrangement of parts for preventing short-circuiting arc-over between terminals during the circuit reclosing operation.

As to certain features of the invention a still 20 further object is the provision of improvements.

in fuse cutouts such as disclosed in my copending application Serial No. 153,529, and in the copending applications of G. F. Lincks, Serial No. 153,508, and L. P. Sohles, Serial No. 153,568, 25 which three applications were filed July 14, 1937, and are assigned to the assignee of the present invention.

Other objects and the details of that which I believe to be novel and my invention will become 30 apparent from the following description and the claims appended thereto taken in conjunction with the accompanying drawing. While, as will become apparent hereinafter, features of my invention may be incorporated to advantage in cut- 35 outs of various constructions and of either the open type or the enclosed type, I have chosen as the best means of conveying a complete understanding of my invention to illustrate and describean exemplary embodiment thereof as in: 40 corporated in an enclosed circuit reclosing fuse cutout of the form shown in the above referred to Sohles application.

In the drawing, Fig. 1 shows the parts of the exemplary cutout in their normal, operative posi- 45 tions; Fig. 2 shows the relative positions of the parts of the cutout after operation of one of the fuses therein; Fig. 3 shows in part the positions occupied by the fuses after drop-out following operation of the final one of the fuses; and Fig. 50 4 is a crosssectional view taken along the line .4 of Fig. 1.

Referring to the drawing, l0 indicates an eleciric cutout casing of the type commonly employed in non-reclos'ing fuse cutout installations.

55 This casing is constructed of porcelain or other suitable insulating material and has an integrally formed electric creepage and gas barrier ll disposed between stationary line terminal contacts I2 and I3 carriedby the casing. To the rear of the casing is-secured a mounting bar 14 for 5 the attachment of the casing to an electric line pole and cross-arm structure or other suitable cutout supporting means. A hinge bracket I5 is secured to the inner face of the rear wall of the casing adjacent the bottom thereof. Contacts I2 and [3 are adapted to have line conductors or leads fastened thereto by means of clamping screws l2 and I3 respectively, and upper contact I2 has a contact finger II backed by means of a spring strip l8 which serves to press the finger l'l' downwardly, and has also a pair of spaced resilient arms l9, one of which is shown in the drawing, which are arranged to receive a fuse holder terminal cap therebetween.

In the exemplary embodiment illustrated, there are provided a pair of fuse holders 20 and 2| of the expulsion type which consist of fuse tubes of insulating material having contact caps 22 and 23 respectively screwed on the upper ends thereof and which have fuse links disposed therein with the upper ends of the fuse links connected respectively to the caps 22 and 23 and the lower ends of the fuse links extending out of the bottoms of the fuse tubes, as indicated at 24 and 25 respectively. Although in the exemplary embodiment, two fuse holders are employed, it will be apparent from the ensuing description that certain features of the invention may be employed to advantage in cutouts having only one fuse holder while other features of the invention may be employed-to advantage in cutouts having more than two fuse holders. The two fuse holders of the illustrated embodiment are maintained in parallel and relatively close side by side relationship by means of a supporting element 26 having openings in which the fuse holders are secured tightly by means of pins or screws 26. Fuse holder 2| is longer than fuse holder 20 and is arranged as illustrated so that its lower open end projects considerably below the level of the lower open end of fuse holder 20 for a purpose to be set forth hereinafter. The fuse holders and their supporting element constitute part of a unitary assembly adapted to be removably installed in a cutout casing, and the fuse holders are arranged so that their axes will be substantially in a plane parallel to the side walls of the width to accommodate a single fuse holder. Thus, the unitary plural fuse assembly may be employed to replace a single fuse holder in the conversion of a non-reclosing cutout to a circuit reclosing cutout, as will become more apparent hereinafter.

A toggle lever 21 is provided for removably supporting the fuse holders 20 and 2| and their supporting element 26 in casing it). One end of this lever is pivotally attached, as by means of a pivot pin 27', to a terminal collar 28 clamped on the lower end of fuse holder 20 and the other end of the lever has a hook-shaped portion 29 for detachable engagement with a hinge pin 30 carried by hinge bracket i5. As will be seen from the drawing, terminal collar 28 normally is electrically isolated from the stationary 'contacts of the cutout by means of a portion of the insulating tube of fuse holder 20. Lever 27 is latched normally in rigid relation to fuse holder 20 by means of fuse link extension 24 which is anchored to terminal collar 28 by any suitable form of clamping device indicated at 3| and which fuse link extension engages a projection 32 on the lever, as shown in Fig. 1.' With lever 21 hingedly attached to bracket i5 and held rigidly to fuse holder 20 and with the unitary fuse assembly in its normal operative position illustrated in Fig. 1, contact cap 22 of fuse holder 20 is latched between spring contact fingers I9 with contact finger l1 pressing downwardly on the top thereof Thus the upper end of the fuse link in fuse holder 20 normally is connected with the upper stationary terminal contact 2 while the lower end of the fuse link in fuse holder 20 normally is disconnected from lower terminal holders 2|! and 2| respectively are electrically connected together by means of a metal clamp 33 which has openings or bores for receiving the fuse holders and which is fastened, by means of a screw or pin 33', to the upper ends of the fuse holders in engagement with the contact caps 22 and 23. In addition to electrically connecting the two contact caps so as to connect the upper end of the fuse link in fuse holder 2i with contact cap 22 and upper stationary contact i2, the clamp serves also to aid in maintaining the fuse holders in proper relationship. On opposite sides of the clamp and adjacent the outer end thereof are bosses 34, each of which has an inner portion 35 of relatively large diameter and outer portion 33 of relatively smaller diameter.

A cutout casing door 40. of suitable insulating material, is attached to the fuse holder assembly by means of a retaining clip 40 secured to the inner face of the door and having spaced resilient arms arranged to receive clamp 33 therebetween. Each of the clip arms has an opening 42 of sufliciently large diameter'to receive the larger diameter portion 35 of one of the bosses 34 and has also an elongated slot 43 in communication with opening 42 but only of sufficient width to receive the smaller diameter portion 36 of one of the bosses 34. Normally the larger diameter portions 35 of the bosses are in engagement with the openings 42 to hold the upper end of the door in its inward position relative to the fuse holders, as illustrated in Fig. 1. By spreading the arms of clip 4| outwardly sufficiently that the smaller diameter portions of bosses 34 may travel in slots 43, the fuse holders may move away from the door to the extent permitted by the length of slots 43, and without complete detachment of the fuse holders from the door. Clip 4| may be rigidly secured to door 40 but is illustrated as being resiliently secured to the door by means of a spring strip 44, eyelet 45, screw 46, and spring 41, as shown in the cutaway portion of Fig. 1. The flexible connection between the door and the fuse holders by means of the resiliently mounted clip has the advantage of to some extent absorbing the recoil of the fuse holder assembly upon fuse operation so that insufiicient recoil is transmitted to the door to cause damaging impact of the upper edge of the door against the cutout casing. It will be seen that with the arrangement just described the door may swing outwardly relative to the fuse holder assembly about the bosses 34. However, the lower end of the door normally is held in its inward position relative to the fuse holder assembly by means of fuse link extension 25, which extension is clamped, by means of a wing screw 50, to the metal terminal 5| carried by an inwardly projecting ledge or boss 52 on the lowerinner face of the door. Terminal 5| is provided with a downwardly extending snubber 53 about which the fuse link extension is wrapped to'insure proper clamping of the extension to the terminal.

In accordance with the teachings of the previouslyreferred to applications of G. F. Lincks and L. P. Sohles, door 40 is of special design 'in that it is formed with a recess on the inner side thereof for the accommodation of fuse holder 2| and the hereinafter described circuit reclosing mechanism which would project beyond the open front of a cutout casing of the type. such as the one illustrated, ordinarily provided in non-reclosing cutout installations. Thus it is made possible to install a circuit reclosing fuse unit of the type illustrated in a relatively shallow casing designed primarily for accommodation of a only a single fuse holder and to have the door properly close the front of the casing 'to prevent exposure of the internal parts to adverse weather conditions. The quick releasable latch provided by clip 4|- permits outward movement of the fuse holder assembly from the door recess to the extent allowed by slot 43 and with out detachment of the fuse holders from the door, to provide ready access to the upper ends of the fuse holders for removal of contact caps .22 and 23 and installation of fuse links in the fuse holders. After installation of fuse links therein, the fuse holders may be snapped back into place in the door recess until the enlarged portions of bosses 34 engage openings 42 of the clip arms to latch the upper end of the door to the fuse holder assembly and the lower end of the door is then latched to the fuse holder as sembly by fuse link extension 25, as previously described,

On the outer side of the door 40 is an integrally formed eyelet handle 56 adapted to be engaged.

for swinging the door and fuse assembly inwardly and outwardly about pivot pin 30. The 'inner side of the door has an integrally formed-barrier 54 with a groove 55 for accommodating the outermost fuse holder 2|. This barrier is disposed opposite the casing barrier I I, which has a groove for accommodating the innermost fuse holder 20, and these two barriers are arranged to cooperate ior retarding the passage of are gases from the lower ends of the fuse holders upwardly into the space around contact l2 in the upper portion of the cutout housing formed by casing I and door 46. However, upon outward movement of the door to indicating position, as described hereinafter, a gap is left between the two barriers which reduces the effectiveness of their retarding action. In order to overcome this difliculty and supplement the retarding action of barriers H and 54, I provide a barrier plate 59, which preferably is of insulation material and which may be either stiff or flexible. This barrier plate rests on fuse holder supporting element 26 beneath and in close proximity to barriers H and 54. As best shown in Fig. 4, the plate has openings through which the fuse holders pass and is arranged to extend transversely of the fuse holders into proximity with the inner walls of casing l0 and door 40.

-As will be noted from the drawing, the barrier plate extends outwardly a considerable distance on all sides of the fuse holders. Thus the barrier plate is arranged to cooperate with barriers II and 54, even when the door is moved outwardly to its indicating position, to effectively isolate from each other the spaces around contacts l2 and I3 and thereby to prevent short-circuiting arc-over due to expulsion gases rising from the lower ends of the fuse holders into the upper part of the cutout housing.

During normal operation of the cutout, the fuse link in the outermost fuse holder 2| is connected between the contacts 12 and IS, the normal circuit extending through contact fingers I1 and I9, terminal cap 22, clamp 33, terminal cap 23, the fuse link in holder 2| and the extenson 25, terminal a .shunt strip 60, supporting element 28, and a contact engaging arm 6|. Arm 6| is pivotally supported on the inner end of supporting element 26 by means of a pivot pin 62 and is biased by means of a coil spring 63 to press against contact I3. The force exerted by arm 6| against contact l3 tends to move the fuse assembly outwardly from the casing, but such outward movement is prevented by the latching of lever 2'47 in rigid relation to holder 20 by means of fuse link extension 24. Shunt strip 60 is fastened at one end to supporting element 26 by one or more screws 64 and at the other end to terminal 5! by one or more screws 65.

In order to secure reclosure of the electric circuit through the fuse link in the inner fuse holder 20 upon operation of the fuse link in fuse holder 2i, there is provided an improved and compact circuit reclosing mechanism which is mounted on the outer end of fuse holder supporting element 26. The details of this circuit reclosing mechanism do not form part of the present invention and are fully set forth in the previously referred to copending application of L. P. Sohles. Hence, only sufiicient of the details will be set forth herein to convey a proper understanding of the present invention. Secured to fuse holder supporting element 26 by means of screw 64 and depending from the's'upporting element is a casing 66 in which is enclosed a time delay mechanism which may be of the mechanical escapement or other suitable type. This time delay mechanism is connected with a switch supporting element 61 which is mounted for vertical sliding movement in guides 68 supported by casing 66. Element 6'! is arranged to be biased downwardly by means of a coiled compression spring which is supported on a rod H and bears against the lower surface of fuse holder supporting element 26. The slidable switch supporting element 67 has a pivot pin 72 upon which is pivotally mounted a switching element having a pair of contact arms 13, one of which is shown in the drawing, which are biased for counterclockwise rotation, as viewed in Fig. 1, by means of a coil spring 14. When contact arms I3 are in their normal positions parallel with slidable supporting element 61 and element 61 is in its uppermost position, the contact arms engage detents carried by fuse holder supporting element 26 to prevent counterclockwise rotation of the contact arms. Switch supporting element 61 and contact arms 13 are maintained normally in their uppermost positions by a pair of spaced projecting feet 16, one of which is shown in the drawing, which form part of terminal 5| on the normally inwardly latched lower end of door 40, and which are arranged to receive therebetween a downwardly projecting extension 11 of the switching element. On the lower end of extenson I1 is a handle 80 which may be grasped for rotat ng contact arms 13 and which may be given any bright color so that it will serve as an indication of fuse operation in a manner to be pointed out hereinafter.

Upon rupture of the fuse link in fuse holder 2|, fuse link extension is released to permit outward swinging of the lower end of door about bosses 34 under the influence of leaf springs H which are fastened to the outer end of fuse holder supporting element 26 by means of the screw 64. As soon as the switching element is released by projecting feet 16, the switching element and its supporting element Bl start to move downwardly under the influence of spring 10. This downward movement is retarded by the timing mechanism in casing 66. When element 67 finally moves down a predetermined amount, the upper ends of contact arms 13 become disengaged from detents 15 so that the contact arms are free for counterclockwise snap action rotation under the influence of spring M, to the position illustrated in Fig. 2 wherein the contact arms engage contacts 82, one of which is shown on the drawing, carried by terminal collar 28 mounted on the lower end of fuse holder 20. In order to provide a good electrical path between contact arms 13 and fuse holder supporting element 26, a flexible shunt strip 83 is fastened at one end to the fuse holder supporting element and at the other end to the switching element of which contact arms 13 form a part. After operation of the circuit reclosing mechanism as just described, the circuit between contacts i2 and 13 extends through contact fingers H and i9, contact cap 22, the fuse link in fuse holder 29, fuse link extension 24, terminal collar 28, contact 82, contact arm 13, shunt strip 83, fuse holder supporting element 26,v and contact engaging arm 5!. Under these conditions, with the parts of the device in their positions as illustrated in Fig. 2, the door is in a partially open position to give indication of operaton of the fuse link in fuse holder 2!, while at the same time providing protection for the internal parts of the cutout from adverse weather conditions.

I Also, handle 80 now projects below the lower edge The time delayed circuit reclosing mechanism 1 temporary fault current in fuse holder 2!.

is so adjusted that, in case of a temporary fault, the contact arms 13 will not be released for engagement with contact terminals 82 until sufiicient time has elapsed for interruption of the If fuse holder 2| terminated at the same lower. level as fuse holder 20 in the compact arrangement illustrated, there would be danger of shortcircuiting arc-over between the conducting parts at the lower ends of the fuse holders due to the gases discharged from fuse holder 2|, which gases tend to mushroom and eddy about fuse link extension 24 and terminal 28. Such .arc-over would result in reclosure of the circuit through the fuse link in fuse holder 20 before the predetermined time interval had elapsed for proper reclosure of the circuit by the time delayed circuit reclosing mechanism and thus the second fuse link would rupture on the same temporary fault which caused rupture of the first fuse link. This undesirable operation is effectively prevented by the expedient, hereinbefore described, of having fuse holder 2! project substantially below the level of the lower end of fuse holder 20. As a result of this expedient, more time elapses before the mushrooming and eddying gases from the lower end of fuse holder 2| approach sufficiently close to the lower end of fuse holder 20 to cause arc-over, and this additional time allows for proper clearing of the temporary fault in fuse holder 2| and proper circuit reclosure by the time delayed mechanism.

In case of continuing or recurring fault on the circuit, the fuse link in fuse holder 20 also operates. Lever 21 then is released by fuse link extension 24 to permit the fuse holder and door assembly to swing outwardly and downwardly, due to gravity and the pressure of contact arm 6| against contact l3, until the parts of the assembly occupy their dropped-out positions indicated in Fig. 3. In their dropped-out positions,

both fuse holders 20 and 2! are completely-disconnected from contacts 12 and I3.

The danger of arc gases rising into the cutout housing to bridge the line terminal contacts upon operation of either fuse holder 2! or fuse holder 20 is greatly minimized, if not entirely removed, by the cooperation of barrier plate 59 with barriers II and 54 and the walls of casing l0 and door 40, which operate, as previously de-.

scribed, to substantially isolate from each other the spaces around the terminal contacts even though the door is moved outwardly to indicating position. This isolating action is materially aided by the expedient of making leaf spring 8| sufficiently broad, as illustrated best in Fig. 4, to substantially bridge the space between the outer end of barrier plate 59 and the inner face of door 40 when the latter in indicating position.

What I claim as new and desire to secure by Letters Patent of the United States is 1. In an electric cutout, a housing including a casing having an open side and a movably mounted door for normally closing said open side, spaced contacts mounted in the housing, a fuse unit including a fuse holder removably supported in the housing for connection of a fuse link in the holder between said contacts, means operative responsively. t operation of a fuse link in said holder for effecting outward movement of said door, and means including a barrier plate supported by said unit in surroundingrelation to said holder intermediate said contacts for substantially isolating from each other the spaces around said contacts, said plate projecting outwardly from said holder a sufficient extent to substantially maintain the isolation between said spaces when said door is moved outwardly.

2. In an electric cutout, a housing including a casing member having an open side and a door member movably mounted for normally closing said open side, spaced contacts mounted in the housing, a fuse holder supported in the housing for connection of a fuse link in the holder between said contacts, means operative responsively to operation of a fuse link in said holder for effecting outward movement of said door member, means carried by'one of said members in at least partially surrounding relation to said holder and projecting toward the otherj of said members for forming a barrier to retard the passage of gases from one end of, said holder toward the other end of the holder, and means including a barrier element supported on said holder in surrounding relation thereto and in proximity to said barrier forming means for cooperation with the barrier forming means to substantially isolate from each other the spaces around said contacts.

3. In an electric cutout, a housing including a casing having an open side and a movably supported door for normally closing said open side, spaced upper and lower contacts mounted in the housing, a fuse assembly removably mounted in the housing and including a fuse holder arranged for connection of a fuse link therein between said contacts, means operative responsively to rupture of a fuse link in said housing for effecting outward movement of said door to a partially open position, said casing and door having means arranged to cooperate when the door is in partially open position for at least partially isolating from each other the spaces around said contacts, and means including a barrier plate carried by said assembly in surrounding relation to said holder beneath and in proximity to said cooperating means for supplementing the isolating action of said cooperating means when the door is in partially open position.

4. In an electric cutout, a housing including a casing having an open side and a movably mounted door for closing said open side, spaced contacts mounted in the housing, a fuse holder supported in the housing for connection of a fuse link therein between said contacts, means for latching said door in normal closed position and arranged to be released upon operation of a fuse link in said holder, a flat spring strip of substantial width disposed between said holder and said door and operative upon release of said latching means to press said door outwardly to a partially open position, and means including said spring strip providing a barrier for retarding the passage of arc gases from the space adjacent one of said contacts to the space adjacent the other of said contacts when said door is moved outwardly upon operation of a fuse link in said holder.

.5. In an electric cutout, a housing including a casing having an open side and a movably mounted door for closing said open side, spaced contacts mounted in the housing, a fuse holder supported in the housing for connection of a fuse linkthereinbetween said contacts, means for latching said door-in normal'closed position and arranged to be released upon operation of a fuse.

link in said holder, and gas barrier means disposed in said housing intermediate said contacts including a resilient member operative upon release ofsaid latching means to cause outward movement of said door to partially open position, said resilient member being disposed in a position to retard passage of arc gases from the space adjacent one of said contacts to the space adjacent the other of said contacts.

6. In an electric cutout, a casing having an open side and spaced terminal contacts mounted therein, a fuse assembly supported in said casing and including a plurality of fuse holders disposed in side by side relationship, a door movably supported for closing said open side of the casing, a circuit reclosing mechanism for successively connecting fuse links in the respective fuse holders in a circuit including said contacts, means operative responsively to operation of a fuse link in one of said holders for effecting outward movement of said door to an indicating position, and a barrier plate carried by said assembly intermediate said contacts for cooperation with portions of said casing and door to substantially isolate from each other the spaces around said contacts when said door is moved to its said indicating position.

7. In an electric cutout of the circuit reclosing type, a casing having an open front and spaced terminal contacts mounted therein, a fuse assembly supported in the casing and including a plurality of fuse holders arranged for successive connection of fuse links in the respective fuse holders in a circuit including said contacts, said holders being arranged in substantially parallel extending side by side relationship with their axes substantially in a plane parallel with the side walls of said casing, a door mounted for closing said open front of the casing, and a barrier plate disposed in surrounding relation to said holders and extending transversely of the axes of the holders into cooperative relation with portions of said housing and door to substantially isolate from each other the spaces around said contacts.

8. In an electric cutout of the circuit reclosing type, a casing having an open front and spaced terminal contacts supported therein, a fuse assembly supported in the casing and including a plurality of fuse holders arranged for successive connection of fuse links in the respective fuse holders in a circuit including said contacts, said holders being disposed in substantially parallel extending side by side relationship with the axes of the holders substantially in a plane extending normal to the rear wall of said casing, a door mounted for closing said open front of the casing, barrier means carried by said door and casing extending at least partially around certain of said holders and arranged to cooperate for at least partially isolating from each other the spaces around said contacts, and a barrier plate in surrounding relation to said holders adjacent said barrier means and extending transversely of the axes of the holders into proximity with portions of said housing and door to supplement the isolating action of said barrier means.

9. In an electric cutout, spaced terminals, a fuse assembly including a pair of fuse holders disposed in substantially parallel and relatively close side by side relationship, the ends of said holders at one end of said assembly being open for the expulsion'of gases therefrom, means for supporting said assembly with a fuse link in one of said holders connected in a circuit including said terminals, and circuit reclosing mechanism operative responsively to operation of a fuse link in said one holder for connecting a fuse link in the other of said holders in the circuit including said terminals, said one holder being arranged with its said open end projecting a substantial distance beyond the said open end of said other holder in order to prevent short-circuiting between said holders during operation! of said mechanism.

10. In an electric cutout; spaced upper and lower stationary terminals, a fuse assembly including a pair of expulsion fuse holders open at their lowerends and supported for connection of fuse links therein between said terminals, said holders being disposed in substantially parallel relatively close side by side relatiiship, one of said holders being longer than th other of the holders and being .arranged so that its lower end projects substantially below the level of the lower end of said other holder, means f normally connecting the upper ends of fuse links in both of said holders with the upper of said terminals, means for connecting the lower end of a fuse link in said one holder with the lower of said terminals, and circuit reclosing mechanism operative responsively to operation of a fuse link in said one holder for connecting the lower end of a fuse link in said other holder with said lower terminal.

11. In an electric cutout, an insulating supporting housing including a casing having an open side and a door for closing said open side, a pair of terminal contacts mounted in the housing respectively adjacent the top and bottom thereof, a fuse assembly removably supported in the housing and including a pair of expulsion type fuse holders disposed in substantially parallel and relatively close side by side relationship, each of said holders having an open lower gas discharge end and one of said holders being arranged with its lower end projecting substantially below the level of the lower end of the other of said holders, means for connect ing a fuse link insaid one holder between said contacts, circuit reclosing mechanism operative respectively to operation of a fuse link in said one holder for connecting a fuse link in said other holder between said contacts, and means including a barrier plate carried by said assembly in surrounding relation to said holders intermediate said contacts arranged to cooperate with portions of said casing and door to substantialy prevent the passage of arc gases from the lower ends of said holders into the space around the one of said'contacts in the upper portion of said housing.

12. A unitary device for removable installation in an electric cutout or like casing having spaced contacts therein, comprising in combination a door for closing an open side of a cutout or like casing, an electric protective assembly attached to the inner side of said door and including a plurality of electric protective elements and means for effecting connection of said elements between spaced contacts in a cutout or like casing, said elements each including an expulsion tube and said tubes being supported in substantially parallel extending laterally spaced relationship, and a barrier element extending transversely of said tubes intermediate the ends of the tubes with a portion of the barrier ele- 13. A unitary device for removable installation in an electric cutout or like casing having spaced contacts therein, comprising in combination a door for closing an open side of a cutout or like casing, an electric protective assembly attached to the inner side of said door and including a plurality of electric protective elements and means for efiecting connection of said elements between spaced contacts in a cutout or like casing, said elements each including an expulsion tube and said tubes being supported in substantially parallel extending laterally spaced relationship with the axes of the tubes substantially in a plane normal to the inner side of said door, and a barrier element in surrounding relation to said tubes and extending transversely of the tubes intermediate the ends of the tubes, said barrier element having a portion 5 isolating from each other the spaces around the 10 spaced contacts in such supporting casing.

RALPH S. BENNETT. 

